Contact lens related
The patient’s description of his/her symptoms, in case of dry eye, is highly pathognomonic.
However, there is no one question which will reveal that dry eye is the leading cause of com- plaints. Listed below are a number of questions related to dry eye symptoms. If patients, who
are suspected of having dry eye, are asked all or most of these questions, correct diagnosis is highly probable, even without detailed clinical examination using instruments and tests avai- lable only to the ophthalmologist. Also, by asking the specific questions listed below, subtypes of dry eye may be defined (hyposecretory or hyperevaporative), this is important, since treat- ment options are different.
SYMPTOMS 1. Duration of symptoms: are they chronic? Of all anterior eye diseases, dry eye is perhaps most clearly defined as chronic. An acute onset of symptoms is never related to dry eye.
2. Symptoms predominantly bilateral? Dry eye symptoms are related to a decrease in function of the apparatus that protects the ocular surface. Therefore, it is never unilateral, except when dry eye is caused by trauma (most frequently chemical) or some neurological diseases.
3. Feeling of dryness in the mouth, presence of rheumatic disease, patient younger than 50?
In case of concomitant dryness of the mouth and rheumatic symptoms, a more serious form of dry eye must be taken into consideration, that is related to systemic disease. Since systemic therapy may be needed, patients with such complaints should be referred to an immunologist and/or rheumatologist.
4. Redness not usually pronounced, intermittent? One of the typical signs of age related dry eye is the virtual absence of conjunctival hyperae- mia, which is present only intermittently. When eyes are really hyperaemic, with an acute onset, the diagnosis of dry eye is highly unlikely. In case of a highly probable diagnosis of dry
eye accompanied by pronounced and persistent red eyes, patients should be referred to an ophthalmologist for further testing.
5. Patient older than 50? Since age related dry eye is the most common type of this condition, the presence of the afo- rementioned symptoms encountered after the age of 50 are highly pathognomonic of dry eye. Almost all patients older than 70 report some dry eye-related symptoms.
6. Symptoms worsening in winter (central heating, cold air) or in a hot, dry climate?
Increased evaporation of tears due to dry air (central heating) and an increased thermal gra- dient between the eye surface and ambient environment (cold air in the morning contains less relative humidity, and rapidly becomes dry when heated near the eye surface!) can invariably be the cause of a dry eye where most symptoms worsen in the winter months. Hot, dry clima-
tes (desert) also increase tear evaporation.
7. Symptoms worsening when working on a computer, reading, or watching TV? Periodic blurry vision that changes (improves) with blinking, especially after longer periods of reading
or watching TV?
Since, on the average, the blink rate decreases fivefold when gazing fixedly, (such as when working on a computer, reading and watching TV), increased tear evaporation exacerbates dry eye symptoms. Tear evaporation increases mainly due to deficient function of the lipid layer, which is secreted from glands in the eyelids when we blink. This complaint is the least age- related one, and occurs in younger age groups more frequently than the other symptoms. Nevertheless, it is definitely related to a decreased protective tear function.
8. Symptoms worsening when driving (ventilation, air conditioning)? The same conditions occur when driving, with the additional element of increased ventilation and dryness of air due to air conditioning in the car. As when working on a computer, this com- plaint typically gets reported by younger patients, who lead more active lives.
9. Symptoms worsening during PMS (for premenopausal women)? Since increased levels of progesterone increase the viscosity of the tear film, borderline dry eye female patients may experience decompensation of their tear film stability during PMS. If pro- perly investigated, this symptom is highly pathognomonic of dry eye.
10. Discomfort while wearing contact lenses? Contact lenses float in the tear film. In case of tear film inadequacy, the eye surface becomes mechanically irritated by rubbing with the contact lens.
Questions to differentiate hyposecretory from hyperevaporative dry eye: 11. Symptoms worse in the morning/evening? Worse in the morning (tearing): Hyperevaporative dry eye (lipid layer deficiency) Worse in the evening (burning): Hyposecretory dry eye (aqueous layer deficiency)
12. Gritty sensation in the eyes, burning, feeling of dryness?
The most common complaint in relation to dry eye is the feeling of hot, burning eyes, with an intermittent gritty sensation, worsening in the evening. This complaint, if properly investiga- t e d , i s o n e o f t h e m o s t d i s t i n g u i s h i n g s y m p t o m s d i f f e r e n t i a t i n g d r y e y e f r o m i n f e c t i v e a n d
allergic conjunctivitis. Feeling of dryness is much more rarely reported, but, when present, is
almost pathognomonic of hyposecretory dry eye. A positive answer to this question strongly suggests hyposecretory dry eye.